The TDK BD-R discs are usually very good quality and the Pioneer BDR-205 is an excellent burner, imho the best one out there ... some of my TDK discs give even better error scans that Verbatims. I've got several SL/DL batches and so far all of them were consistently high quality...
Which TDK discs are you using? What is their rated speed (2x, 4x), what is the media code (you can check that with DVDIdentifier), are they jewel cased or a 10pk, 25pk or 50pk spindle, are they made in China, Japan or UAE?
Also are you writing these discs at their rated speed or overspeeding them?
Maybe the quality of the prticular batch you're having is not quite what it should be ... In that case, if they are 4x discs, you might try burning them at 2x and see if that solves the problem, or if you burn them at a higher speed than their rated speed then try burning them at their advertised speed.